Selective control device for radio aparatus and the like



R. W. MAY SELECTIVE CONTROL DEVICE FOR RADIO Filed ma 14, 1947 I lzsheets-shget 1 INVENTOR ATTZZ? R. W SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE MAY Oct. 11, 1949.

12 Sheets-Sheet 2 Filed May 14, 1947 INVENTOR Get. 11, 1949. R. w. MAY 2,484,638

SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE Filed May 14, 194'? 12 Sheets-Sheet 3 BUMP!) IV /A r INVENTOR ATTORNEY Oct. 11, 1949. R. w. MAY 2,

SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE Filed May 14, 1947 12 Sheets-Sheet 4 H mm MIL-El Illlllllllllllllllll III Ill-MINA Illlllll mum-ill Ill-n. ll Illllllllllllll F/ fi/h/FD 14 MA y INVENTQR ATTORNEY Oct, 11, 1949. R. W.'MAY 2,484,638

SELECTIVE CONTROL DEVICE FOR RADIO i APPARATUS AND 1mm LIKE Filed May 14, 1947 12 Sheets-Sheet 5 ,INVENTOR ATTORNEY Oct. 11, 1949. w, MAY 2,484,638

SELECTIVE CON'IRO EVICE R RADIO .APPARA'IUa D THE L Filed May 14, 1947 1 2 Sheets-Sheet 6 FIG.6.

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SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE 12 Sheets-Sheet 7 Filed May 14, 1947 IbTIVENTO R WW4- ATTORNEY R. W SELECTIVE CONTROL DEVICE FOR RADIO Oct. 11, 1949. .MAY

APPARATUS AND THE LIKE Filed May 14, 1947' 12 Shets-Sheet s w w M w H a Q W// 1 WW w f fi A g 7 Z 5 M w W "M M W W W FIG.- 8.

130mm /4 MA) INVENTOR ATTQRNEY Oct. 11, 1949. w. MAY

SELEC E TROL DEVICE FOR'RADIO PA US AND THE LIKE Filed May 14, 1947 12 Sheets-Sheet 9 F 9 kF/b/mat I/MAY INVENTOR BY M ATTORN Y Oct. 11, 194 9.

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ATTORNEY Oct. M, 1949. w.-MAY

SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE Filed May 14, 1947 12 Sheets-Sheet 11 mOPOE INVENTOR 2%ufi1 7K ATTORNEY Oct. 11, 1949. w, MAY 2,484,638

SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE Filed May 14, 1947 12 Sheets-Sheet 12 INVENTOR ATTORNE relented Oct. 11, 1949 SELECTIVE CONTROL DEVICE FOR RADIO APPARATUS AND THE LIKE Richard W. May, Cedar Rapids, Iowa, assignor to Collins Radio Company, Cedar Rapids, Iowa,

a corporation of Iowa Application May 14, 1947, Serial No. 748,054

33 Claims. (Cl. 192142) This invention relates to automatic positioning mechanisms and more particularly to a control device for selectively determining the angular orientation of a rotatable shaft which is designed to undergo either a fractional revolution or one or more complete revolutions before arriving at a final selected orientation.

While devices according to the invention have been found particularly useful in the selective positioning of tuning elements or circuit control elements of radio apparatus, such for example as radio transmitters and receivers, it will be clear from the following disclosure that the principles of the invention can be embodied in any apparatus which is required to determine with utmost accuracy the angular orientation of a control shaft.

The invention is in the nature of an improvement upon the type of tuning control mechanism disclosed and claimed in application Serial No. 472,717, filed January 18, 1943; application Serial No. 515,250, filed December 22, 1943, and in various prior issued patents of Arthur A. Collins of which Patent #2,285,4l4, granted June 9, 1942, is typical. 1

In certain kinds of radio equipment employing a control shaft, such for example as a tuning condenser shaft, the complete tuning range can be effected by a single complete rotation of the shaft. In other kinds of radio equipment of which the well-known permeability or slug tuner is typical, the tuning motion is rectilinear and usually requires a control shaft which must be capable of undergoing more than one complete rotation in order to cause the tuning element to move over its complete positional tuning range. For simplicity of reference, the first type of device will be referred to herein as a single turn selecting control, and the second will be referred to as a multi-turn selecting control.

Accordingly, it is a principal object of this invention to provide an improved arrangement for automatically and selectively controlling the angular positioning of a control shaft, regardless of whether. the said shaft is required to make more than one complete revolution or only a fractional revolution.

It is also an object of this invention to provide an improved device having interlocked electrical and mechanical control for selectively operating a multi-turn control shaft to a desired selected setting.

The type of device disclosed in said Patent 412,285,414, and in said pending application, employs a plurality of selector drums known respectively as a stop ring drum and a pawl selecting drum, in conjunction with a series of selectively shiftable and rockable pawls which pawls selectively engage recesses or notches in the said drum to determine the stopping of the shaft. The present invention has for another object a device which possesses the operating and control advantages of the said prior devices, but without requiring the use of such rockable pawls.

Another principal object of this invention is to provide a multi-turn shaft positioning device whose selective stopping requires the conjoint alignment of two separate selector members whose relative positioning with respect to a set of fixed stops, can be initially and independently adjusted to provide the equivalent of a Vernier action in determining the desired stopping position for said shaft.

Another object is to provide a compact device for automatically controlling the tuning of a radio set or the like with a high order of accuracy.

A feature of the invention relates to a selective shaft-setting arrangement comprising a pair of selector drums which are selectively rotatable around parallel axes, one of the drums being selectively movable longitudinally with respect to the other drum to determine the number of complete revolutions of said other drum which are necessary to bring the said shaft to its final desired setting.

Another feature relates to a selective shaftsetting arrangement, comprising a pair of selector drums which are selectively rotatable around parallel axes, one of the drums being a turns-counting drum for the other drum, in conjunction with a series of fixed stop members common to both drums for determining the final stopping of said shaft.

Another feature relates to a selective shaftsetting arrangement, comprising a plurality of drum-like members rotatable around parallel axes and each carrying a plurality of stopping teeth which can be independently preset in any desired circumferential orientation around the respective drum axis, in conjunction with a set of fixed and longitudinally spaced projections whereby the said shaft can be stopped in a selectecl position determined by the planar alignment of a single tooth in each drum and a single one of said spaced projections.

Another object relates to a selective shaft-setting arrangement, comprising a plurality of drum-like members rotatable around parallel axes each carrying a series of radially projecting teeth which can be independently preset to any desired circumferential orientation around the respective drum axis, in conjunction with a plurality of fixed and longitudinally spaced projections; the planar alignment of one of said projections with a tooth in each of said drums determining the selective setting of said shaft, and means being provided for positively locking the said planarly aligned teeth and the said projection in fixed abutting relation.

Another feature relates to a selective setting arrangement for a rotatable shaft which is capa ble of being turned through more than one complete revolution to a final desired setting, the arrangement comprising a pair of rotatable around parallel axes and each carrying independently presettable stopping teeth; one of the drums being a turns-counting drum and slid-able with respect to the other drum and the sliding position thereof being controlled by an automatic selector switch of the circuit-seeking type, the circuit-seeking memberof which is movable as a unit with the said sliding movement of said turns counting drum. I v

A further feature relates to a device for selectively setting a, rotatable shaft which is capable of being turned through more than one complete revolution to a final desired setting, the device comprising a pair of rotatable toothed drums one of which is a turns-counting drum for the other drum and is formed in two separate sections which are independently slidable with respect to the said other drum for planarly aligning one tooth on a turns-counting drum section with one tooth on the said other drum, the relative angular displacement of said plana'rly aligned teeth determining the additional fractional turn which the said shaft is to undergo in order to arrive at its final setting.

A further feature relates to a device for selec-' tively setting a rotatable shaft which is capable of being turned through more than one complete revolution to a final desired setting, the device having a turns-counting drum carrying a pin rality of independently presettable radial teeth, said drum being formed of two sections which are rotatable as a unit but with the sections rela tively slidable under control of a circuit=seeking automatic switch, the seeking elements of which is moved as a unit with the said drum sliding movement. I

A still further feature relates to a shaft setting device having a pair of toother drums with the teeth in each drum independently presettable around the drum; one of the drums being rotat able as a unit with the said shaft and the other drum being selectively rotatable and slidable to determine the number of revolutions for the other drum. The said sliding movement of said other drum is selectively controlled by an automatic switch of the circuit-seeking type, both drums operating with a fixed comb, the longitudinal spacing of the teeth on said drums being unequal so that for any given desired setting of said shaft, only a single tooth on each drum is in planar alignment with a single tooth of said comb.

A still further feature relates to a shaft-setting device of the type having a pair of rotatable selector drums each carrying a series of independently. presettable radial projections, with the longitudinal spacing of the projections on each drum being unequal so that for any given desired setting of said shaft, only a single tooth on each drum is in planar alignment with a single tooth on the other drum.

A still further feature relates to a shaft s'tting device of the type having a primary selector drum and a secondary selector drum, both drums being relatively rotatable and one of the drums being relatively shiftable with respect to the other drum, the said shifting movement being controlled by an automatic circuit-seeking switch and by a rotatable cam together with an electrical interlock between the switch and cam to selectively stop the cam when the movable member of the seeking switch arrives at the selected contact.

-A still further feature relates to a shaft-setting device of the type havin a primary selecting drum and a secondary selecting drum, each carr'ying a series of stop teeth in conjunction with a fixed comb so that the drums can be stopped only when a single tooth on each drum is in mutual abutting relation with a single tooth on the 'fixed comb together with special means operated in timed relation with respect to said drums to lock them in their final selected prisition.

A 'still further feature relates to the novel organiZation, arrangement and the relative interconnection and positioning of parts which cc operate to provide an automatic control unit for radio sets and the like.

Other features and advantages not specifically enumerated will be apparent after a considera tion of the following detailed descriptions and the appended claims.

Figs. 1, 2, 3, 4 and 5 are respectively right side view, left side view, bottbin view, top view and front View of a device according to the invention.

Fig. 6 is a rear View, with part of the rear plate removed, to show more clearly certain of the dew ing gears.

Fig. '7 is a cross section of Fig. 5, taken along the line 1-'-7 thereof, and viewed in the direction or the arrows.

Fig. 8 is a cross section of Fig. 1, taken along the line 8-8 thereof, and viewed in the direction of the arrows.

Fig. 9 is a cross section of Fig. 1, taken along the line 99 thereof, and viewed in the direction ofthe arrows.

Figs. 10A-, 10B, 100, show the stopping control elements in three difierent stages of the opera tion of the device.

7 Fig. 11 is a composite schematic diagram of the electrical controls usable with the device, and with certain mechanical portions of the device also illustrated chematically.

Fig. 12 is a partial perspective view of part of the mechanism for locking the device in its selected positions.

Fig. 13 is a detailed cross-sectional view of part of the device.

Referring more particularly to Figs. 1 to 4, the various working parts of the device are supported in operative relation by a frame work coil"- sis'ting of a front plate l0 and a rear plate H, which are united by fourshoulde'red tie rods l2, ['3 I4, l5, and respective fastening nuts l6. Also extending between the plates 10, II, is a metal bar l1, having a set of ten inwardly projecting teeth l8al87' (see Figs; 3,- 9, 10A, 10B, 10C) constituting what may be termed a stopping comb for purposes to be described.-

Tlie shaft [9 which is to be selectively positioned is mounted for rotation in suitable bear-'- ings in the plates l0 and II, and is arranged to be coupled to the adjusting or tuning element of a radio apparatus, such for example as the pertype of permeability tuner such as used in the radio art. It will be understood of course, that the invention is not limited to any particular tuning or adjustment device but. is panticularly adapted to a tuning device which is arranged to undergo either a fractional turn, or one or more complete turns before it arrives at its final selected position. For example, in the case of the wellknown permeability tuner, the core 20 is coupled to a threaded shaft 29a which is in threaded engagement with a fixed threaded abutment 291), so as the shaft 20a turns, it moves the core 20 longitudinally a predetermined extent. In order to effect the maximum longitudinal adjustment of the core 20, it is necessary to turn the shaft 29a through a number of complete turns. In the particular example to be described, it will be assumed that the device 29 requires for its maximum longitudinal adjustment, ten complete turns of the shaft 29a, and when the shaft 20a has been given the required number of complete turns it is given an additional fractional turn so as accurately to locate the core 29 within its inductive winding 20c.

Shaft l9 (see Fig. 7) carries a series of ten stop rings 2la2lj, each ring having a single radial projecting stop tooth 22. These stop rings are unevenly spaced apart along shaft 19 by a series of intervening spacers 2311-232. The stop rings with their intervening spacers may be considered as a single stop ring drum which is arranged to rotate as a unit with shaft 19, but wherein each of the stop rings can be individually preset with its tooth at the desired radial position, whereupon the stop rings can be clamped so as to rotate as a unit with shaft l9. To effect this, the rings and spacers are clamped together as a pile-up by means of an annular shoulder 24 which is set into shaft i9, the opposite or forward end of that shaft being hollow to receive the end of a clamping screw 25 which carries at its forward end a clamping wing nut 26. In engagement with the unthreaded end of member 25, is a bar 21 which passes transversely through a slot 28 in the shaft l9, this bar abutting against the gear 29 which transmits rotary motion to shaft l9 and which also acts as the other clamping member for the said pile-up. For this purpose, gear 29 is slidably adjustable on shaft l9 so that when the member 25 is turned in one direction, it forces gear 29 against the end of the pile-up and consequently when the gear 29 is driven in the manner described hereinbelow, it rotates shaft 19 and the stop ring drum as a unit. Located between each stop ring 2i and one of the adjacent spacers 23-, and also between the gear 29 and the first stop ring 2 la, is one of a series of thin metal discs 3fla-397'. It will be observed that the shaft [9 has a flat 3|, and the discs War-307' have corresponding flats so that they are compelled to 60 rotate with the shaft l9. On the other hand, the stop rings Zia-419 and the spacers 23a23i do not rotate with shaft l9 until they are clamped together as a unit between gear 29 and member 24. Preferably, the discs 39a3llg' have flexible peripheries and the right-hand face of each of the spacers 2312-232 is undercut so as to provide only an annular shoulder which engages the adjacent disc 30. By this arrangement, when nut 26 is backed up to relieve the clamping pressure, it is possible to preset any one or more of the stop rings around shaft 19 without disturbing the previous settings of the remaining stop rings. By reason of the flexible periphery of the thin metal disc 3ll'ct30i, this presetting is Since the stop ring drum has ten presettable stop rings, it is then possible to selectively stop the shaft I9 in any one of ten predetermined angular positions of any complete turns.

Also mounted in suitable bearings in the plates III, II, is another shaft 32 (see Figs. 4, 5, '7, 8 and 12) which is rotated in reduced speed relation with respect to shaft l9, so that shaft 32 undergoes only one revolution for each 12 revolutions of shaft l9. For this purpose, shaft l9 has fastened thereto a pinion 33 which drives the speed reducing gear train 3438 (see Figs. 1 and 6). Mounted for sliding movement on shaft 32 are two counting drum sections 39, 40, which count the number of complete turns through which the shaft I9 is to be selectively rotated. In the particular example shown, the shaft I9 is arranged to undergo a fraction of one turn to ten complete turns. The counting drum section 39 consists of a set of five stop rings 4la4li, each ring having a single stopping tooth 42. The stop rings lla-Me are unevenly spaced by intervening spacers wa -430i and between each spacer and the adjacent stop ring is one of a series of thin fleXible-margined metal discs l ia4fie. As in the case of the spacers 2'3a-23i, the spacers 43al3d are undercut on their side faces. The turns-counting drum section 40 likewise consists of five single toothed stop rings 4 IfMy' with the intervening spacers 43e 4311., and intervening flexible thin metal discs nf-447'.

Each of the two pile-ups constituting the drum sections 39 and 49 is carried by a corresponding sleeve 45, 56 (see Fig. 7), which has its bore at one end provided with a flat to engage the corresponding flat on the shaft 3'2. Each sleeve has at one end an integral flange ll, 18, against which the corresponding pile-up is clamped. Also fastened to the sleeves are respective retainer rings 49, 59 against which the opposite ends of the respective pile-ups are clamped. The periphery of each sleeve 44, 95, has a flat to engage the corresponding fiat in each of the discs Moi-441i. However, the stop rings and spacers of these drum sections, when the stop ring drum is unclamped, are capable of being individually adjusted and preset around the shaft 32. The clamping pressure between the elements of drum 39 is effected by a bowed spring 5i. Likewise, the clamping pressure between the elements of drum section 49 is efiected by a bowed spring 52.

As pointed out above, the shaft 19 is required to undergo either a fraction of a turn, to as much as ten complete turns, and is required to be selectively stopped at any preselected point during the particular selected turn. In other words, the drum sections 39 and to constitute a turns-counting drum, and the stop ring drum on shaft l9 constitutes the radial angular setting drum.

The stop rings in the drums are so spaced by their respective spacers, that for any desired setting of shaft 19, one and only one, stop ring of the series Zia-2M, can be in planar alignment with one of the stop rings llalla'. In other words, the rotation of the counting drum sections 39, 40, and their selective sliding movement on shaft 32 determine which one of the toothed stop rings of the turns-counting drum sections is in abutting locking engagement with the-tooth of the desired stop ring 2 lat-2M. Therefore, the previous angular setting of the stop rings 2 Ia-Zlj will determine the extent of incremental rotation or fractional turn that shaft 19 will have to undergo after it has completed its desired number facilitated. of complete turns undercontrol of the counting drum sections 39, 40, in order that the shaft l9 shall arrive at its final selected position. In other words, the stop rings 2la-2lzi and the stop rings 4| a-4lj, are unevenly spaced so as to provide in conjunction with the fixed teeth l8a-l87' above described, a Vernier action so far as the rotation of shaft I9 is concerned.

Referring to Figs. 10A, 10B and 100, it will be seen that the shaft [9 can be stopped in its clockwise motion only whenthe tooth '22 of a stop ring 21 is in planar alignment with the tooth 42 of a stop ring 4!, and only when the tooth 42 is in alignment with one of the fixed teeth iii of the series Ilia-4 87'. This relation is shown in Fig. 103,

which represents a final selected or at rest position of the shaft l9. Unless the three elements 22, 42 and E8 of any given set are in .planar alignment, it will be clear therefore that the shaft I9 is not stopped. The final stopping of shaft 19 is therefore determined by the particular one of the teeth 22a22:i, which is in planar alignment with one of the teeth 4241-427, and with one of the fixed teeth I8 of the series l8a-l8y'.

Before the device undergoes its selecting movement, it is returned to a normal or homing position in which case the shaft [9 is rotated in a counter-clockwise direction (as seen in Fig. 10A). Fig. 100' shows the device undergoing its selecting movement, wherein the shaft I9 is rotating clockwise and the shaft 32 is rotating counter-clock- Wise, and just before tooth 22 engages tooth 42 and tooth It. In order positively to lock the shaft IS in its final selected position, that is, in order to lock the elements 22, 42 and I8 (Fig. 1013), in their abutting relation, there is provided an elongated pinion 53 which at the end of the selective cycle is rotated clockwise (as seen in Fig. 1013) through a small angle. Pinion 53 is in mesh with the gear sectors 5455, Eli-51 (Figs, 7 and 12). Sectors 54 -55 are integrally united with an arcuate plate 5.8 to form therewith a rocker cradle, and the forward edge of member 58 is formed with a series of f ve curved teeth 5'9a-59e, which are in planar alignment with the respective rings Ha-M c. Likewise, the gear sectors 56-5l, are integrally fastened to a curved plate 60 having a series of curved teeth 59f59j, which are in .planar alignment with the rings 41 f4 |7'. The members 54- 5! have openings through which the shaft 32 freely passes, and when the pinion 53 is rotated as abov en ion d, it cau e the t h 91' to be moved into abutting engagement with the particular tooth 22 which is in engagement with the select d oo 42 nd e fi e oo as shown in. Fig- 10138 Th m ha r s in this locked relation until a new setting of shaft i9 is desired.

A coiled tension spring 6| (Figs. 2 and 1 2) is fastened at opposite ends to the plates 54 and 51 so as normally to urge two rocker frames and their respective drum sections 39, 40, towards each other. Thus, as the left-hand drum section 39 moves along shaft 32, it carries with it the teeth 59q59e. Likewise, as the drum section 40 moves alon shaft 32, it carries with it the teeth 59f-59j. For purposes of clarity in the drawing, the two drum sections are omitted in the perspective View of Fig. 12. The spring 6! tends tg pull the drum sections 39, 40, together so that their adjacent ends abut against a ridge 62 on shaft 32. In this position, the lug 63 attached to member 53 abuts against a radially extending pin 64 on a slidable cam follower 65. Also the lug 66 attached to member 60 engages the said pin 64. The follower 65 is adapted to be selectively moved in either direction and to be stopped at a desired point in its travel. When the follower 65 moves to the left, it likewise moves the drum section 39 to the left but without disturbing the drum section 48. This relation of the drums is shown in Figs. 1, 3, 4 and '7. On the other hand, when the follower 65 moves to the right, it moves the drum section to the right but without disturbing the drum section 39 which however is moved to a position against the ridge 6? by spring 6|.

As will be described, the follower 65 is moved in either direction by a two-way lead screw 6'1. Thus by making the turns-counting drum in two sections each of which is movable independently of the other, and by using a two-way lead screw 61, the overall linear movement of the turnscounting drum as a whole is reduced by one-half and each drum section 39, 40, can be made identical. That is to say, the spacers ita-Eiid can be identical in width with the spacers fi3i-43e. If a singie continuous drum were employed, the spacers i3a43i would all have to be of unequal widths so that only one stop ring of the counter drum can line up with a stop ring 2 |a2 Ii. This arrangement also reduces the overall length of the device.

In order to limit the total number of turns to which the shaft l9 can be turned in either direction, there is fastened to shaft 32 an arm 'shaft ll.

88 (see Figs. 4, 8 and 12). At the limit of rotation of shaft 59, that is to say, at the end of the tenth complete turn, arm 68 engages a pivoted latch 69 to urge the latter into the path of the locking bar 21, thus preventing further rotation of shafts l9 and 32. The latch 69 is normally held by spring 10 out of the path of arm 27.

Thus, after ten complete revolutions of shaft 89, starting from the reference or home position, the arm 68 urges the latch 69 into the path of the locking bar 2! to stop shaft [9. This stopping action is necessary in order to establish a starting point or home position for the mechanism. Without this limiting action after the conclusion of the maximum number of turns for which the device is designed, the device might be damaged.

For the purpose of controlling the selective longitudinal movement of the drum sections 39, it, there is provided a timing and control shaft "H which is supported in suitable bearings in plates I 0 and H, and extends parallel to the shafts l9 and 32 (see Figs. 2, 3 and 6). Shaft '1 l is driven by the pinion 72 through idler gear 13, which meshes with gear 14, fastened to shaft ll, pinion 12 being driven by a suitable reversible electric motor 15, fastened to the depending portion of plate H. The front end 16 of shaft "H is threaded and engages a threaded follower Tl. Follower H has a peripheral groove '18 (see Fig. i3) in which is located a split ring 19, the ends 86 and 3! of which slidabiy engage the plate 82 which is fastened by screws 83 to the rod it. Thus as shaft H rotates, the follower 11 is constrained to move either to the right or left, depending upon the direction of rotation of said The arrangement is such that when the follower 17 reaches the end of its transit in one direction, the pin 34 engages a pin 85 extending through shaft H, so that follower 11 is constrained to rotate with the shaft. Another pin 86 carried by the follower 11, engages the dog 87 carried by one of the metal discs of a friction disc clutch 88. Consequently, the cylindrical cam 61 is then rotated in unison with the rotation of shaft I I. It should be observed that cam 61 is in the form of a sleeve which is rotatable around shaft 'II but is suitably prevented from sliding movement on that shaft. This cam has a pair of reversely pitched cam grooves or threads. The end of cam 61 also carries an integral disc 89 having four locking notches 89a (see Figs. 2 and 3) located 90 apart around the disc periphery. Cam 'I'I continues to rotate until the pivoted armature 90 of a control relay 9I is deenergized to allow the latchingend of this armature to enter one of the notches 89a to restrain further rotation of cam 61. Relay 9I is suitably fastened to plate II and carries two sets of contact springs 92-93 (Fig. 11), and 94-95-96, which control the application of current to the motor 15 and which also control its direction of rotation.

The cam follower 65 has fastened to its periphery by screw 91 (see Fig. 9) a pair of metal fingers 98, 99, which slidably engage opposite faces of strip 82, so as to prevent rotation of the follower while providing an electrical grounding connection to the'frame of the device. Also fastened to follower 65 is an arm I00, which carries at its end a wiper contact or brush IOI, arranged to wipe over a series of fixed bank contacts I 62a-I02y'. The wiper IIJI isarranged to make contact with neutral contacts I 03, I04, when the device is to be manually operated. Preferably, the fixed bank contacts are carried by an insulator strip I05 fastened by screws I06 to the rod I4, suitable circuit connecting lugs I91 being provided for the respective fixed contacts. The brush I! and the fixed contacts constitute an automatic selector or finder switch, and the fixed contacts are wired respectively to corresponding fixed bank contacts IBM-I087 of a remotely located manually settable rotary switch I32. Arranged to wipe the contacts of the selector switch I32 is a metal disc I09 having a peripheral notch H0 for purposes to be described. The arrangement is such that the cam follower 65 sweeps the brush I Ill back and forth across the contacts I92a-I 929' until an ungrounded contact is reached, which ungrounded contact represents the selected setting for the tuning device 20. During the sweeping motion in one direction, the drum 39 is moved in unison with follower 65; while in the opposite sweeping motion the other drum section All is moved in unison with the follower.

In the at-rest position of the device, that is after it has completed a selective cycle, the follower 11 (Fig. 2) is at the extreme right-hand end of thread I6, but before it reaches this extreme position and just after the drums have been selectively positioned with the desired teeth 22. 42 and E8 in abutting planar alignment (see Fig. 103), the opposite end of pin 84 engages a clutch plate III which has a central opening through which shaft II freely passes. Until this plate III is engaged by .pin I6, it is held in its right-hand position (Fig. 2) by a pair of retractile springs H2, each having one end anchored respectively to the rods I4, I5, and the other end of each spring being hooked to diagonally opposite points on plate HI. Plate I II has a notch in its periphery in slidable registry with the guide plate 82 so as to prevent the plate from rotating. Plate I I I is also integrally joined by arms I I3, to another plate I I4, through which shaft II freely passes. Plate H4 has three arcuate recesses H for purposes to be described,

Cit

' shaft 1a to rest.

Also freely surrounding the shaft II in spaced relation to plate H4 is a similar plate H6 (see Fig. 8) having a set of three arcuate recesses II'I, similar to and adapted to register with the recesses H5 in plate H4. A ball bearing H6 is provided in each pair of opposed recesses and these recesses have their bottoms of opposite inclination so that when the plate H4 is forced to the right (Fig. 2) by nut 11, the plate H6 is turned through a definite angle. A spring H9 is locate between the bearing flange I20 and plate H6 and normally presses the plate II6 against the balls. Located between the hub of plate H5 and the face of gear I2I, is an end thrust ball bearing I22, and fastened to shaft 'II is a driving disc I23. Located between disc I23 and the face of gear I2I, are friction discs I24. Thus, before pin 64 engages plate III, the

tension of springs II2 maintains gear I2I infrictional driven engagement with shaft II, and therefore rotates the stop ring drum, since gear I2I is in mesh with gear 29. On the other hand, when pin 84 engages plate III at the end of the selecting cycle, the tension of springs I I2 is overcome, thus breaking the frictional drive between I23 and I 24 and bringing the stop ring drum and A slight additional movement of nut I1 moves clutch plates II I and H4 to the right and by reason of the inclined faces in the cooperating arcuate recesses in plates H4 and H6, the latter plateis turned through a predetermined angle.

Pivotally fastened to plate H6 (see Fig. 8) at I25a, is a bifurcated member I25 which has one of its jaws provided with gear teeth in mesh with a sector gear I26 fastened to shaft I21 and to which is also pinned the pinion 53. A spring I28 normally holds the member I25 in the position shown in Fig. 8 in which position the teeth 59a. are out of the path of the stopping ring teeth 22. However, when plate H6 is turned as above described, the member I25 is moved against the tension of spring I28, causing a corresponding rotation of sector gear I26 and of the pinion 53. This rotation of pinion 53 rotates the rocker frames 54-55, 56-51, whereby the teeth 59a-597' are moved to the position shown in Fig. 103, wherein one of these teeth 59a-597' is in planar alignment with a single one of the teeth 22 on the stop rings, shown respectively in the homing position, the final selecting position, and the setting up position.

Mounted on the insulating strip I05 which carries the selective bank contacts tom-m2? is a flexible contact spring I29 (see'Figs. 4 and 8) which carries an operating button I3I, and this spring is normally closed on its associated contact spring I36 when the device is undergoing homing and selective operation. However, when the selectin cycle is completed and the member I25 is moved to lock the parts in their mutual stopping relation, the said member I25 engages the insulating button I3I attached to spring I29 to finally open the circuit of motor 15.

As mentioned above, in connection with Fig. 2, shaft H drives gear I2I through disc clutch I23-I24. Gear I2I drives the tuning control shaft l9 through gear 29; while on the opposite end of shaft I9 the pinion 33 drives the turnscounting drum sections 39, 40, through gears 34-38. This gear train 34-38 is selected so that the turns-counting drum sections rotate through approximately 330 while the shaft l9 rotates 11 through its maximum number of turns, for example ten.

Before describing the complete sequence of op= erations in setting up a new position for shaft I9, reference should be had to Figs. 10A, 10B, 100, which are simplified sketches of the essential cooperating stopping parts for shaft I9. In Fig. 103, the mechanism is at rest in its set-up selecting position and with one of the turns-counting drum stop teeth 42 abutting against the fixed tooth I8; and with one of the teeth 22 of the stop ring drum clamped between 42 and 59. When a new position for shaft I 9 is required, the member I09 of the manual selector switch I32 is rotated, causing the motor I to rotate the stop rings 2Ia--2I7 ina counter-clockwise direction (Fig. A). Previous- ,to this operation however, the clamping teeth 5912-597 are moved in a clockwise direction out of the path of the stop ring teeth 22a-229. These rotations of 2Ia-2I 'i and of 4Ia4I9' continue until the parts reach the position shown in Fig. 10A at which time the arm 68 (Figs. 1, 4 and '7) and latch 59 cooperate with bar 21 to positively stop shaft 09. This represents the home or refence position, wherein the pin 86 engages the dog 87 and causes rotation of the cylindrical cam 61, thus moving the brush I00 in search of the ungrounded bank contact I02a-Ill29'. By reason of the fact that the cam 61 has two cam slots of op pos'ite pitch so long as the said cam continues to rotate, it causes the brush ID to move first in one direction and then in the opposite direction so as to completely traverse the bank of fixed contacts.

Also, as the said brush I99 movesback and forth seeking the ungrounded contact, the turns-counting drum sections 39, MI, are moved in unison axially therewith, first one section being moved and then the other until the ungrounded contact is found. When brush I00 reaches this ungrounded contact, the relay 9I is deenergized to cause arma ture 99 to latch with the notch in disc 89, lockingthe cam S'I and brush I09 against further movement. This leaves only one stop ring 2Ia-2Iy' in such a position that only one of the stop rings 42a 42 i in the turns-counting drum sections is in planar alignment therewith. When relay M is deenergized, it causes reverse rotation of the motor thus driving the rings 2Ia-2I7' in clock= wise direction, and the rings 4Ia4 I 7 in counterclockwise direction, this rotation continuing until the proper teeth I8, 42 and 22 are in mutual abut ting and stopping relation (see Fig. 103). Thereupon, the disc clutch I23, I2 8, slips, and after sufiicient time delay the pinion 53 is rotated to lock the parts in selected position.

Fig. 11 shows in generalized schematic form. the electric controls and certain of the mechanical parts, all of which bear the same designation numerals as the corresponding parts in Figs. 1-10. The parts are shown in Fig. 11 at rest with the tuning device 29 in a position corresponding to contact I980; of the manual selector switch I32. When it is. desired to move device 20 to a different setting, for example that corresponding to contact 387', member I 99 is turned manually to bring the notch IlIlinto registry with contact I08 The previously ungrounded contact I920. as well as the interveniet contacts asstite; are thereueon grounded, completing a circuit from the grounded. me ber 32;, brush 91a, brush ml, Contact I02a, contact IOBa member I 99, conductor I33, winding of relay 9!, and thence through the grounded battery or other power source I 34. The operation of relay 91 connects this power source through the relay contacts to the winding of motor 15, causing 12 the shaft II to rotate in such a direction as to retate the stop rings 2Ia--2I'g' counter-clockwise; and rotating the turns-counting rings 4Ia=4lj clockwise to a home or reference position.- In this position; nut 11 engages and drives the cam 61. As this cam rotates, by reason of its double reverse cam grooves it causes the brush IIII to slide back and forth over contacts I02a l02i. This axial movement of brush IIII is coordinated with the back and forth movement of the drum sections 39, 40. When the contact I92j is finally reached, the above described circuit for relay 9| is open; causing this relay to release its armature 99 which thereupon enters into blocking engage ment with the disc 89 on the oath 67; thus prevent= ing any further rotation thereof and therefore locking brush IBI in its selected position. The release of relay 9| also reverses the direction of the current to the motor I5 which thereupon turns shaft II in such a direction as to rotate the stop rings 2Ia-2Ia' clockwise and the counting drum rings Mae-4! counter-clockwise. By reason of the previously described axial setting of the drum section the appropriate ring 429' is now in planar alignment with the stop ring 2I and also with the corresponding fixed tooth I87; The parts are therefore in their mutual stopping position as represented in Fig. 193, and nut I1 engages the clutch plate III resulting in the turning of pinion 53 and the teeth 59a-591 to leek the parts in this mutually stopped position. It should be ob-' served that the threaded portion I6 of shaft II is such as to enable a suflicient time to elapse before pinion 53 is turned to lock the parts,- thus accommodating the maximum number of turns that shaft I 9 may have teundergo, for example ten. F

Shortly after nut TI has reached the limit of its movement in the settingeup direction, the member I25 (Fig. 8) which controls the locking movement of teeth 59a-.599', engages the limit switch button I31 and opens the limit switch contacts I29, I 30, andthe motor power circuit, whereupon the motor I5 comes to rest. The parts are now positively locked in their selected or set-up si e t should it be desired to change the relation between any bank contact (for example contact I027) and the particular angular setting of the shaft I9, this can be done byautomatically posi-. tioning shaft I9 as above described, then uh loosening nut 26 tcunciamp the pile-lip of stop rings. The shaft I9 is then free to be manually turned by knob I34 to the desired angular setting. This causes a change in the relative radial posinot crtocth 2| around shaft I9, but without disturbing the p'r''v eus radial Settings of the re:- meming teeth Zia-=2 m. The turning-of shaft is being geared t0 the counting drum shaft 32, as shaft I9 is tii'rnd for the new presetting' adjustment, it automatically presets the counting dlilm shaft. This leaves the latter such a panties that it cpufits tut the proper number of complete tiirhs of shaft before selective steppin occurs as tove aescribee The nut 25 can then, be tightened ts clamp the pile-us sf step rings, and the device is in readiness for any dsiied automane setting.

ssuming that thedevie M is to be moved to difi'erent positions to represent different awn queasy manners, the renewing win summarise the sequence of operations necessaryto 'e fieetuate a channel selection.

1. The new channel is selected by turnin the manual selector switch Iiz so that its match [It is in registry with the seared channel contest.

2. Relay 9| operates and supplies power to the driving motor 15.

3. Motor 1'5 rotates the power shaft 1 l 4. Follower Tl backs away from clutch ii i and moves the locking fingers 5911-597 away from the stopping ring teeth.

5. Gear I2! is clutched to shaft TI rotating the stop ring drum and the turns-counting drum sections towards home position.

6. After reaching home position, follower 11 engages pin 85 and immediately thereafter causes rotation of cylindrical cam 61.

'7. The finder swtch wiper lill is driven by the cylindrical cam to seek an open circuit and simultaneously the cylindrical cam moves the counter drum sections axially.

8. When an open circuit is found by the finder switch wiper llll, relay 9| is deenergized to lock the cylindrical cam against rotation and at the same time to reverse the motor rotation.

9. The engagement of the armature of relay H with the notch in the cam disc 89 accurately lines up one, and only one, stop tooth of the appropriate counting drum 39 or tllwith a corresponding stop ring 2| and a corresponding stationary finger I8.

10. The counting drum by reason of the 12 to 1 gear reduction with respect to the stop ring drum serves to count the number of complete revolu" tions required for the main shaft I9.

11. When the selected stop finger on the appropriate counter drum reaches the stationary finger l8, it provides a fixed stop for the corresponding lined-up stop ring tooth 22, thus preventing any further rotation of shaft I9.

12. The driving clutch I23, I24, slips because the stop ring drum is positively stopped, and this slipping continues until the follower l'l reaches the clutch plate Ill, whereupon the locking fingers 59L-59i are rotated into locking engagement.

13. The limit switch contacts I29, I30, are then opened to break the motor supply circuit.

14. The tuning cycle is complete and the shaft I9 is positioned as desired.

What is claimed is:

1. Apparatus of the character described for selectively setting a rotatable shaft which is required to undergo either a fractional revolution or more than one complete revolution before arriving at its selected setting, comprising a pair of separate rotatable members each carrying a plurality of stop elements, a fixed comb mounted adjacent said rotatable members and having a series of teeth one for each of said stop elements and adapted to be aligned therewith for effecting stopping of said shaft, the stop elements on at least one of said. members being independently presettable, and the stop elements on both members being spaced apart so that for any given setting of said shaft a single stop element on one member is in planar alignment with a single stop element on the other member, means to rotate said members relatively to each other,

and means to move said members longitudinally relatively to each other to bring any desired stop element on one member into planar alignment with a selected stop element on the other member and with a tooth on said comb and thereby to determine the extent of rotation of said shaft.

2. Apparatus of the character described for selectively setting a rotatable shaft which is required to undergo either a fractional revolution or more than one complete revolution before arriving at its selected setting, comprising a pair of 14 separate rotatable members each carrying an equal number of stop elements with the stop elements on each member being differently spaced with respect to the stop elements on the other member so that for any desired setting of said shaft only a single stop element on one member is in planar alignment with a single stop element on the other member, and means to selectively shift the stop members longitudinally with respect to each other to determine which stop elements on the respective members are to be in planar alignment and thereby to determine the extent of rotation of said shaft.

3. Apparatus according to claim 2 in which one of said members is fastened to said shaft to be.

rotated as a unit therewith, and means are provided for driving both said members to respective homing positions and thereafter reversing the rotation of said members until the selected stop element on one member is brought into abutting relation with the corresponding selected stop element on the other member.

4. Apparatus of the character described for selectively setting a rotatable shaft which is required to undergo either a fractional revolution or more than one complete revolution before arriving at a selected setting, comprising a pair of rotatable members each carrying a series of stop elements unequally spaced longitudinally of the axis of rotation of the members and arranged to form a pluralit of different stop combinations for said shaft, each stop combination being defined by an abutting engagement between a single stop element of one member and a single stop element of the other member, and means to rotate said members relatively to each other and to move them longitudinally with respect to each other until a selected stop element of one member is brought into abutting relation with a selected stop element on the other member.

5. Apparatus according to claim 4 in which one of said members is driven as a unit with said shaft, and means are provided for driving the other member at a reduced speed with respect to the first member. I I

6. Apparatus according to claim 4 in which the stop elements of at least one of said members are mounted thereon for independent presettable adjustment around the rotational axis thereof.

7. Apparatus according to claim 4 in which each of said members is in the form of a drum constituted of a series of single-tooth stop rings releasably clamped between spacer elements.

8. Apparatus according to claim 4 in which each of said members is in the form of a drum constituted of a series of stop rings each carrying one of said stop elements, the stop rings on at least one of said drums being unequally spaced along the length thereof and capable of independent presetting around the rotational axis thereof.

9. Apparatus of the character described, comprising a primary rotatable shaft to be selectively set, a secondary rotatable shaft driven in fixed 7 but reduced speed relation with respect to the 75 secondary shaft.

-10. Apparatus according to claim 9 in which the stop elements on said secondary shaft are selectively slidable therealong.

11. Apparatus'according to claim 9 in which the stop elements of said secondary shaft are slidable therealong, and an automatic switch of the circuit-seeking type is coupled to said slidable stop elements to selectively determine the extent of said sliding movement.

12. Apparatus according to claim 9 in which a set of fixed stop members are mounted in planar alignment with the stop elements on the said primary shaft to provide a fixed step for the said abutting element of said shafts.

13; Apparatus according to claim 9 in which a set of fixed stop members are mounted in planar alignment with the stop elements on said primary shaft, a set of shiftable stop members are provided in planar alignment with the stop elements on the secondary shaft, and means are provided for shifting said shiftable stop members as a unit to lock the said abutting stop elements on the primary and secondary shafts against a corresponding one of said fixed stop members.

14, Apparatus according to claim 9 in which said stop elements on the secondary shaft are slidable bodily therealong, a fixed stopping comb is provided having its teeth in planar alignment with the stopelements of the primary shaft, and a shiftable stopping comb is provided with its teeth in planar alignment with the stop elements on the secondary shaft and slidable as a unit therewith, the said shiftable comb being normally out of the path of movement of the stop elements on both said shafts.

15. Apparatus of the character described, comprising a primar shaft to be selectively set, a secondary shaft, a plurality of single-tooth stop rings carried by the primary shaft, a corresponding plurality of single-toothed stop rings carried by the secondary shaft, a fixed comb having its teeth in planar alignment with the stopping rings on said primary shaft, and means to rotate the said shafts in predetermined speed relations and to shift the stop rings on both shafts longitudinally with relation to one another to bring into mutual abutting relation only a single stop ring toothon each of said shafts and a single tooth on said comb to provide a positive selected stop against further rotation of said primary shaft.

15. Apparatus according to claim 15 in which a shiftable comb is provided having its teeth in planar alignment with the stop rings on the secondary shaft, and means are provided for shifting said shiftable comb to lock said abutting teeth on said primary and secondary shafts in mutual abutting relation with said singletooth on said fixed comb.

17. Apparatus according to claim 15 in which primary and secondary shafts are rotated in opposite directions to effect said abutting relation of said teeth.

r 18. Apparatus according to claim 15in which the stopping rings on said primary shaft are independently presettable therearound and means are provided for releasably clamping them in their preset position.

19. Apparatus according to claim 15 in which said stop rings are unequally spaced on their respective shafts by intervening spacers, and means are provided for releasably clamping the rings to the primary shaft for independent presetting adjustment therearound.

28. Apparatus of the character described, comprising a primary shaft to be selectively set, a

16 secondary shaft, said shafts being parallel to each other, a primary stop ring drum carried by the primary shaft, a secondary stop ring drum carried by the secondary shaft, each drum having 5 a series of single teeth spaced unequally apart along the drum length and spaced apart around the drum circumference, the said drums being rotatable with their respective shafts, means to permit the drum on the secondary shaft to move longitudinally thereof, a fixed comb having its teeth in planar alignment with the stop rings on said primary shaft but having for any desired setting of said primary shaft only a single tooth in planar alignment with a single tooth on said secondary drum, means to selectively slide said secondary drum to bring a desired tooth thereon into planar alignment with a tooth on said comb, means to rotate said secondary drum to bring the said desired tooth into stopping engagement with said single tooth on said comb, and means to rotate said primary drum in the opposite direction to the rotation of the secondary drum to bring a single tooth on said primary drum into stopping engagement with said single tooth on the secondary drum, andthereby to stop said primary shaft at its desired setting.

21. Apparatus according to claim 20 in which said comb is mounted with respect to said drum so that the stopping teeth of the primary drum cannot be stopped by the teeth of said comb until a stopping tooth of the secondary drum is rotated into abutting relation with a tooth an said comb.

22. Apparatus according to claim 20 in which another shiftable comb is provided having teeth in planar alignment with the stopping teeth on said secondary drum, but normally out of the path of rotation of the said teeth on both drums, and means are provided for automatically shifting said shiftable comb to lock the abutting teeth of the primary and secondary drums against a corresponding aligned tooth on said fixed comb.

23. Apparatus of the character described, com: prising a primary rotatable shaft to be selective- 45 ly set, a secondary rotatable shaft, a plurality of stop elements carried by the primary shaft and spaced along the length thereof, a plurality of stop elements carried by the secondary shaft and spaced along the length thereof, the relative spac- 50 ings of the stop elements on the respective shafts being predetermined so that for any desired selective setting of said primary shaft only a single stop element thereon is in planar alignment and abutting relation with a single stop element on the secondary shaft, the stop elements on one shaft being movable longitudinally with respect to the stop elements on the other shaft, and means for effecting the said longitudinal movement, the last-mentioned means comprising a rotatable cam, a cam follower for translating the rotary cam movement into rectilinear movement of said member and of said longitudinally movable 'stop elements.

24. Apparatus according to claim 23 and having a reversible motor geared to said shafts for rotating both said shafts first to a home position and then in a reverse direction to a final selective setting, electric circuit means for controlling said motor, and means responsive only when said shafts have reached home position for closing said motor control circuits to effect said longitudinal movement.

25. Apparatus according to claim 23 and having a reversible motor which is geared to both said shafts for rotating them first to a home position 

